All I Want For Christmas
by ipreferwestside
Summary: The thought crosses his mind a little too late that he should have called first. She might not even be home, might have company, maybe even a guy. He doesn't think she's seeing anyone, but despite their still-tender almost-friendship, Kate is still very private. A Christmas fic written for 2015 Castle Secret Santa. COMPLETE


I don't want a lot for Christmas  
There is just one thing I need  
I don't care about the presents  
Underneath the Christmas tree  
I just want you for my own  
More than you could ever know  
Make my wish come true  
 _All I Want For Christmas_ \- Mariah Carey

* * *

 **ALL I WANT FOR CHRISTMAS**

* * *

The thought crosses his mind a little too late that he should have called first. She might not even be home, might have company, maybe even a guy. He doesn't think she's seeing anyone, but despite their still-tender almost-friendship, Kate is still very private.

Unfortunately, he doesn't think about that until after he's already knocked on her door. He stands there for a few minutes, feeling slightly awkward with the wrapped box in his hands, and is just about to turn around when the door opens. His eyes flick down her body before his brain can tell them not to; she's wearing a fluffy robe, her feet and legs bare, and her hair is tied in a messy bun at her nape.

She blinks at him in surprise. "Castle. What are you doing here?"

Castle's fingers tighten around the box, and he takes a step back, stumbling a little. "I'm sorry, Beckett. I'm interrupting something. I'll just—I'll see you tomorrow."

Kate snags his sleeve before he has a chance to run away, and tugs. "I was just finishing a bath. Do you wanna come in?"

"I should—"

"Come in, Rick."

The use of his first name propels him forward; she always calls him by his surname, save a handful of times. He's only heard her call him Rick when she's upset at him, or when she wants him to shut up and take her seriously. So he shuts up and steps inside, hears the slide of the deadbolt when she locks it behind him. He turns to her, eyebrow raised.

Kate shrugs one shoulder. "Can't be too careful." Her eyes flick down to his hands. "What's up?" she asks pointedly, offering the box a little nod.

Castle startles at the question. "Oh! Well, I got you something for Christmas. I thought I'd bring it by." He thrusts it towards her. This is a weird feeling, how he's suddenly nervous and a little clumsy. Then again, he's never been in the presence of a robe-clad Kate Beckett before.

The corners of Kate's mouth lift in a slight smile. "Castle, you didn't have to get me anything."

"I know, but I thought of you when I saw it, and I wanted to get it. And I—" He pauses to swallow around the sudden lump in his throat. "I consider you a friend."

Kate flushes at his words and ducks her head. "I consider you a friend too," she admits quietly. "Make yourself comfortable, I'll be right back."

As she retreats from the living room he can't help but watch her go, at her long legs, the slight curve of her hips and her ass—

"Stop staring, Castle."

He huffs, but as soon as she's out of sight he turns his attention to the rest of her living room and the adjoining kitchen. His eyes land on the bookshelf that adorns one wall, and he steps closer when he sees a row of familiar spines on the top shelf.

"Yes, I have your books."

Castle turns at the sound of her voice, and he lifts an eyebrow at the admission. "Told you I had a fan," he teases, taking a step closer, words from their first meeting coming back to him. "'Fan of the genre' my ass."

"Shut up," Kate mutters, turning to the couch in the middle of the living room. She's changed into leggings and a worn NYPD hoodie, her feet no longer bare but enclosed in bright red fuzzy socks. There's a small gift bag on the coffee table, and Castle sets the box he's still holding next to it. "Can I offer you anything? I have wine, beer, I could even make some coffee—"

"No, I'm fine," Castle interrupts. She's rambling and it's cute, but he's way too excited about her gift and wants her to open it. "Here," he says excitedly, settling on one end of the couch. "Merry Christmas, Beckett."

Kate sits on the opposite end and gives him a cautious look as she reaches for the box. Her teeth trap her bottom lip while she opens it carefully, first untying the ribbon, then trying not to rip the paper that's so precise and neat.

"You can tear it, I won't mind."

She shuts him up with a glare, but Castle sees the smile flirting with her lips when she gives in and simply tears the paper to reveal a box. "Castle," she breathes as she lifts the flaps open, and pulls a sweatshirt out of the tissue paper. She glances over at Castle, who's grinning from ear to ear. "Castle, this is—"

"Look at it, Kate." Castle's practically bouncing in his seat, his fingers gripping the cushion so he doesn't reach out and take it from her.

Kate unfolds the sweatshirt, and barks out a laugh at the Batman logo that adorns the chest. The design continues to the waist, to a façade of Batman's utility belt. But it's the hood that has her throw her head back in laughter. It has two triangles on top, so if she's wearing the hood, it looks like the bat ears from the helmet.

Finally, Castle can't help himself, and he shifts forward on the couch, inching closer. "Do you like it?" When he'd seen it he'd immediately thought of a conversation in his office, shortly into their partnership, and he'd recalled her lack of denial at being a Batman fan.

"Oh my God, Castle," Beckett manages before her eyes widen and she stands. "Hold on, I have to show you something."

Castle reaches out and fingers the tissue paper peeking out from the gift bag in front of him. He didn't expect anything from her; he'd truly only gotten the sweatshirt on a whim, off of some website he'd stumbled across. He would have given it to her on her birthday, so she wouldn't feel obligated to return the favor, but it hadn't arrived in time. "I hope it's the right size," he called out. "I know you wear a small, but you're tall, I figured a medium would be more comfortable. But I can exchange it if you want—"

"No, it's perfect," Beckett calls as she walks back into the living room. She stands in front of him, and grins when his jaw drops. "Great minds really do think alike."

Castle chuckles. She's wearing another Batman hoodie, this one with a large, distressed logo that sits on the right side of the off-center zipper and covers the whole left side. "Or at least very similarly," Castle manages as his chuckle grows, and soon they're both laughing.

After a few moments, Kate is back on the couch, their laughter subsiding. "Thank you, Castle," she says sincerely; she's swapped sweatshirts and is now wearing the one he got. Her fingers play with the zipper, and she looks him straight in the eye, a smile on her face. "I love it." She nods her head towards his gift. "Your turn."

Castle normally opens his presents with gusto, throwing tissue and wrapping paper every which way so he can see what lies beneath. But Kate leans back against the arm of the couch, her feet tucked beneath her and her hands on her knees. Her lip is trapped in her teeth again, and he can tell that she's a little timid.

He'd noticed the lack of decorations in her apartment, so he could only assume that Beckett didn't do Christmas. Deep down, he wonders if it has to do with her mom; according to her file, Johanna had been killed just a few weeks after Christmas, so maybe it was too close for Kate? But Castle wasn't about to ask that question, not after he'd almost ruined their entire partnership mere months before.

No, that chapter was done, until Kate opened it.

So he takes his time with the gift, lifting off the paper he'd been toying with earlier, then reaching into the bag to bring out a small box. When he opens it, he gasps. It's an NYPD mug, one he knows she can get easily. But when he turns it around, he can only open his mouth in surprise.

Opposite the NYPD icon, there's a drawing of two bulletproof vests: one that says "POLICE" and one that says "WRITER." Castle stares for a moment, his fingers brushing over the vests, and when he finally looks back at Beckett, he knows the shimmering in her eyes match his own.

"Kate, this is…"

"I know it's just a mug, but I thought you'd like your own NYPD mug. You're always eyeing mine, and then I had Lanie draw those vests, and I had it made, that way you can tell that it's yours," Kate says quickly, and she shuts up when Castle's hand covers her own.

"It's perfect," he whispers, his voice rough with emotion and awe at the woman in front of him. Because he knows that this isn't just a mug: it's her way of saying that they're okay, they're partners again. "Thank you, Kate." He punctuates his words with a gentle squeeze of her fingers.

Kate flushes. "You're welcome. Thank you for mine."

"You're welcome." Castle can't stop looking at her, can't stop studying her eyes, watches as they darken from their usual light hazel to almost brown as her breath starts to quicken. He's just about to lean forward, to dust his fingers along her jaw and pull her in for a kiss, when her phone pings.

Kate looks away with an apologetic smile, and grabs her phone from the sofa table. She looks at it, takes her hand back to quickly type something, then sets it back down. "Sorry," she says, looking back at Castle. "My dad. He went up to his cabin, wanted to let me know he got there safely."

"Good." Castle sighs and stands, wincing as his back pops when he stretches. "I should go, it's late, and I totally imposed." He grabs his mug, pauses and considers for a moment, then puts it back in the gift bag. The last thing he wants to do is break it; no, this mug is going on a shelf in his office.

"You didn't impose," Kate insists, but follows him to the door anyway. She sets her hand on the deadbolt, but waits until his scarf and coat are back on before unlocking it.

He feels her eyes on him while he shifts his shoulders, settling into his coat, and adjusts his scarf so it will cover his whole neck from the bitter chill of the New York December night. Tomorrow is the 23rd, and although he'll be joining her at work if a body drops, he feels different tonight. It feels like they've made a step forward in their partnership, in their friendship.

He watches out of the corner of his eye as Kate worries her bottom lip again – that's going to be the death of him – her face mired with indecision, and is surprised when she takes his gloved hand in hers. He barely has a chance to react before she's bracing herself on his shoulder and brushing a kiss on his cheek, and her lips are gone before he can even blink.

"Thank you, Rick," she says quietly, almost shy. They're simple words, but he thinks there's more to them, that she's not just thanking him for the gift.

Castle smile and squeezes her fingers briefly before letting go. "Thank _you,_ Kate." He hopes she hears the subtext behind his words too; he's not only thanking her for the mug, but for allowing him back into her precinct, into her life. "See you tomorrow?"

Her smile brightens. "Tomorrow."

 **-FIN-**

* * *

 _AN: Written for Secret Santa 2015, as a little gift to ijustwantanevilqueen aka Annalise. A little something set in your favorite season. Merry Christmas!_

 _AN2: The sweatshirts exist! The first one, that Castle gives her, is at www dot sammydress dot com slash product2365888 dot html, and the one Beckett already had is www dot sammydress dot com slash product2076489 dot html. Or go to sammydress dot com and search "Batman sweatshirts." Thank you for reading!_


End file.
